In demanding industrial, chemical, and high-purity environments, the selection of tubing material is critical. PTFE Molded Tube stands out as a premier solution, offering an unparalleled combination of chemical resistance, thermal stability, and electrical properties. Unlike extruded tubes, molded tubes are manufactured through a meticulous process involving the compression molding of fine-grained PTFE resin, resulting in a product with superior dimensional consistency, enhanced structural integrity, and the absence of voids or contaminants. This makes it the go-to choice for applications where reliability is non-negotiable.
Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer renowned for its inertness. Its unique molecular structure, featuring a robust carbon backbone shielded by a dense layer of fluorine atoms, grants it exceptional resistance to nearly all industrial chemicals and solvents. This, combined with a wide operational temperature range and excellent dielectric strength, makes PTFE Molded Tube an indispensable component across various sectors, including semiconductor manufacturing, pharmaceutical processing, chemical plant plumbing, and automotive systems.
Our PTFE Molded Tubes are engineered to meet the highest standards. Below is a detailed breakdown of our standard product specifications. Custom configurations are available upon request to meet specific application requirements.
| Parameter | Standard Value / Range | Test Method / Notes |
|---|---|---|
| Standard Inner Diameter (ID) | 1 mm to 100 mm | Custom sizes outside this range available. |
| Standard Wall Thickness | 0.5 mm to 10 mm | Wall uniformity is guaranteed by the molding process. |
| Density | 2.15 - 2.20 g/cm³ | ASTM D792 |
| Tensile Strength | 25 - 35 MPa (3,600 - 5,000 psi) | ASTM D638 |
| Elongation at Break | 300 - 500% | ASTM D638 |
| Dielectric Strength | > 40 kV/mm (in air) | ASTM D149 |
| Volume Resistivity | > 10^18 Ω·cm | ASTM D257 |
| Chemical Resistance | Excellent to virtually all chemicals | Resistant to strong acids, bases, and solvents. Attacked only by molten alkali metals and certain fluorine compounds. |
| Water Absorption | < 0.01% | ASTM D570 |
What is the primary difference between a PTFE Molded Tube and a PTFE Extruded Tube?
The primary difference lies in the manufacturing process. Molded tubes are created by compacting PTFE resin in a mold under high pressure and then sintering it. This results in a denser, more dimensionally stable, and void-free product with superior mechanical properties, ideal for critical sealing and structural applications. Extruded tubes are forced through a die, which can be more economical for long, continuous lengths but may have slight variations in wall thickness and can be more susceptible to stress cracking.
Can PTFE Molded Tubes be used for applications involving ultra-high purity water or chemicals?
Yes, this is one of their primary applications. The non-porous nature of molded PTFE prevents any leaching or absorption of contaminants. Its extreme chemical inertness ensures that even ultra-pure water or aggressive chemicals like hydrofluoric acid or concentrated sulfuric acid will not degrade the tube or be contaminated by it, making it essential in semiconductor, pharmaceutical, and biotechnology industries.
What are the temperature limits for continuous operation of a PTFE Molded Tube?
PTFE Molded Tubes can operate continuously within a temperature range of -200°C to +260°C (-328°F to +500°F). At the upper end of this range (around 260°C), the material may undergo some thermal softening, but it will not melt. It remains flexible and functional at cryogenic temperatures without becoming brittle, which is a significant advantage over many other plastics and elastomers.
Is PTFE tubing resistant to UV light and outdoor weathering?
While PTFE has excellent chemical and thermal stability, it can be susceptible to degradation from prolonged exposure to direct ultraviolet (UV) light and extreme outdoor weathering. The material can become embrittled and surface-chalk over time. For outdoor applications, it is recommended to use PTFE tubing with protective jacketing, specify carbon-black filled PTFE for enhanced UV resistance, or ensure the tubing is shielded from direct sunlight.
How do I connect or assemble PTFE Molded Tubes into a system?
Due to its inertness and low coefficient of friction, PTFE cannot be solvent-welded or easily adhesively bonded. Common assembly methods include using compression fittings with ferrules (e.g., Swagelok-style), flanged connections, and push-to-connect fittings. It is crucial to ensure that the fitting design is compatible with the rigidity and wall thickness of the molded tube to prevent leakage or damage. For permanent installations, heat welding or thermal bonding by a skilled technician is also an option.
Are there any chemicals that can damage or degrade PTFE tubing?
PTFE is one of the most chemically resistant polymers available. However, it can be attacked under specific extreme conditions. These include exposure to elemental fluorine, certain fluorine compounds (like chlorine trifluoride), and molten alkali metals (e.g., sodium or potassium). At very high temperatures and pressures, some perfluorinated fluids can also cause slight swelling. For nearly all other industrial chemicals, solvents, and acids, PTFE Molded Tube offers complete resistance.
Can PTFE Molded Tubes be sterilized for medical or food-grade use?
Absolutely. PTFE Molded Tubes are excellent for sterile applications. They can be effectively sterilized using all common methods, including autoclaving (steam sterilization at high temperatures), gamma radiation, ethylene oxide (EtO) gas, and electron beam processing. The material will not degrade or lose its properties during these sterilization cycles, and its USP Class VI and FDA compliance make it suitable for implantable devices, drug delivery systems, and food processing equipment.
What factors should I consider when specifying the wall thickness for my application?
Selecting the correct wall thickness is critical for performance and longevity. Key factors include the operating pressure of the system (thicker walls handle higher pressures), the need for flexibility (thinner walls are more flexible), the requirement for kink resistance (thicker walls resist kinking), and the compatibility with your chosen connection fittings. Our engineering team can assist in calculating the optimal wall thickness based on your specific pressure, temperature, and mechanical requirements.